This morning I tried tubular tyres for the first time; it was only a short ride because I wasn’t feeling great. I traversed a few small hills, did a bit of work on the flat, and experienced a variety of road surfaces: decent tarmac, potholed tarmac and brick paving to name a few.
I naïvely began this experiment with the idea of comparing tubular tyres to clincher tyres and reaching some kind of definite conclusion. This is, of course, not going to happen. All I can do in fact is compare Continental GP 4000S clinchers on Campagnolo Zonda wheels to Vittoria Corsa SC tubulars on hand-built wheels (Mavic Reflex rims/Dura-Ace 9000 hubs). There are a lot of differences there which are not strictly related to the change of tyres: the spoke lacing is very different (probably the Zondas are stiffer in that area), the rims are very different (the Zondas are narrower and deeper and again stiffer; the Reflex rims are lighter), the hubs are very different (both are top-quality but only the DA-9000 hubs have the recently-popularised very large axle design which should act to stiffen up the whole bike), and of course the tread of the tyres is very different.
You may ask why I did not eliminate the tread difference by using the Continental GP 4000SR tubular, or indeed the Vittoria Open Corsa SC clincher. My reasoning, flawed as it may be, is that I should compare the reference clincher to the reference tubular. I am fairly certain that the best widely-available clincher is the GP 4000S: this is what the majority of un-sponsored people who race on clinchers race on. I am also reasonably certain that the Open Corsa SC is the best widely-available tubular: it (or the closely-related Open Corsa CX) is what I see most often on the bikes of those who aren’t sponsored to race a particular tyre.
Anyway, is there a difference? Yes. Which is better? It’s not that kind of difference, or at least I do not yet think it is. It seemed to me that the tubulars were more communicative about the state of the road surface: when it is generally smooth tarmac with subtle changes in grip level you feel like you know what’s going on, but when it is rough tarmac it feels harsher. Single bumps are smoothed out nicely but the brick paving was a killer. It must be said that I have only done one ride (at 123PSI for the front tyre and 128PSI on the rear) and Vittoria recommend lower pressures than this for ‘wet/rough’ roads for riders of my weight. I also haven’t done the same amount of riding on brick paving on the GP 4000S, and it may be as bad or worse.
I did feel that the tubulars were faster possibly because they are lighter, possibly because they have much lower rotational inertia, and possibly because the tread makes a cool whooshing noise at high speeds on smooth roads. I do not have enough data yet to make any analysis of whether they are or are not faster.
They are certainly good enough to stay on my bike for a while; there is no immediately compelling reason to switch back to the GP 4000S. I think I owe it to the experiment to get approximately as much riding experience on these as I have on the GP 4000S clincher before I write my final assessment.